Circuit controlling device



Jan. 16, 1934. L. P. HUTT 1,944,084

CIRCUIT CONTROLLING DEVICE Filed Jan. 25, 1932 Fig. I.

Inventor:

H is Abborn ey.

Patented Jan. 16, 1934 I UNITED STATES PATENT OFFICE-" 1,944,084 CIRCUIT CONTROLLING nnvron Leonard P. Hut t, Schenectady N. Y., assignor to .General Electric Company, a corporation of- New York Application January 23, 1932. Serial No. 588,360 I s 3 Claims. (01. 200-81) My invention relates to circuit controlling deditions. A handle is provided for returning the vices, more particularly to pressure operated biased member to its inoperative position so that switch mechanisms such as used in connection it may be re-engaged by the thermal responsive with refrigerating apparatus. strip when it has returned to its normal position.

Automatic circuit controlling devices of the A spring member attached to the movable switch 60 class described are usually provided with a switch member is engaged by means of a finger carried mechanism normally biased to the open posibythe reset member which maintains the switch tion. A pressure "responsive device in the form in the open position so long as the handle is' in of a metallic bellows in response to varying the reset position. Thus, if the reset handle is pressures moves the switch from open position tied in the reset position it' will be impossible 65 to closed position. An overload device is usually to close the switch either manually or in response provided for causing the switch to be opened to the varying pressures in the metallic bellows upon overload conditions and to be maintained insuring protection of the apparatus under the in the open position until the overload device is control of the control device.

reset. This is usually done by means of a re- Referring to the drawing, Fig. 1 shows a top (0 setting device in the form of a manually operated view of the control mechanism including my inlever which returns the overload mechanism to vention; Fig 2- shows a portion of the switch normalposition. mechanism after the overload mechanism has In the, type of switch described in my-cobeen tripped in response to overload conditions? pending application, Serial No. 432,204, filed Feb- Fig. 3 shows the position of the reset mechanism 75 ruary 28, 193Q, and assigned to the same assignee and overload mechanism with the reset handle as the present invention, a manually operated in the reset position.

- handle is provided for positively returning the In Fig. 1 a base 10 supports the stationary. conoverload mechanism to normal position. It has tact ll flof the switch mechanism. A movable been found that where the voltage regulation of member 12 pivoted at 13 carries the movable con- 80 the power lines to which the device is attached tact 14. Alever 15 pivoted at 15' and operated by is poor, more or less frequent tripping of the means of the metallic bellows member 16 is operoverload mechanism results. The user of'the ably connected to the movable member 12 by apparatus upon which this control device is means of spring 17 and link 18 which 'produce a mounted would in many cases tie the resetting snap action of the movable contact 14 in a 85 handle in the reset position thereby rendering manner well known to the art. A spring 19 the overload, mechanism inoperative which of biases the lever 15 to the position shown toniaincourse would eliminate the 'protection provided tain the contacts 11 and 14 open. The compresfor. overload conditions. sion in this spring can be varied by means of The invention'of my said copending application lever 20 and adjusting knob 21. The overload 90 was made prior to the present invention and I, mechanism comprises the lever 22 pivoted at 13 therefore, do not herein claim anything shown or and biased in a counter-clockwise direction by described in said copending application which is .means of the biasing spring 23. Themember 22 to be regarded as prior art with respect to this is normally held against its bias by means of the present application. thermal responsive strip 24 whichhas mounted 95 Aprincipal object of my invention is to proadjacent thereto the grid 25. The grid becomes vide an improved type of circuit controlling deheated upon overload conditions and causes the vice of the above described class in which the thermal responsive strip 24 to bend outwardly to switch cannot be closed manually or automatirelease the end of the lever 22. This permits the cally so long as the overload reset handle is main spring 23 to rotate the lever 22 in a counter- 0 tained in the reset position. clockwise direction about its pivot 13 to move In the preferred embodiment of my invention the movable switch member 12 to the open posithe switch member isoperated in the usual mantion. The rest of the control mechanism shown ner by means of a metallic bellows device reupon the base 10 is not pertinent to the present sponslveto varying pressures. An overload meminvention and is therefore not described except to ber biased to move the switch member from say that the mechanism shown generally at 26 is closed position to open position is normally maina relay. I F tained in its inoperative position against its bias A reset handle 2'7 is provided with a finger 28 by means of 'a thermal responsivestrip which which cooperates with the beveled portion 29 v 55 releases the biased member upon overload conupon the member 22 to return it to the position v shown in 1 as will be described below. A relatively stifl spring 30 is carried by the movable switch member -12 and cooperates with the finger 28 to hold the switch member 12 in the open position as shown in Fig. 3 so long as the handle 27 is maintained in the reset position.

In Fig. 2 it will be seen that the thermal element 24 in response to overload conditions has moved outwardly and released the end of the member 22 which in response to the biasing spring 23 has moved in a counter-clockwise direction and is engaging the movable member 12 and holding it in the open position. In Fig. 3

' the reset handle 27 has been moved to the reset position and the bellows 16 is shown in the position for closing the contacts. However the switch cannot close until the member 22 is again latched into position. The finger 28 cooperates with the beveled portion 29 of the lever or tripping member 22 to rotate it in a clockwise direction to return it to normal position. The thermal element 24 having cooled re-engages the end of the tripping lever 22 to hold it against its bias in the normal position. The finger 28 also cooperates with the spring 30 to hold the movable member l2 in the open position as the finger 28 is' moved along the beveled portion 29 and as shown will continue to hold the member 12 in that position so long as the handle 27 is in the reset position as shown in Fig. 3. The bellows 16 cannotmcve the switch member 12 to the closed position so long as the handle is in the position shown.

It will thus be seen that I have provided a unique and eflective device for preventing the switch mechanism from being moved to the closed position so long as the resetting mechanism is in a position to render the overload protective mechanism inoperative.

While I have described my invention in concrete form and as operating in a specific manner in accordance with the provisions of the patent statutes, it should be lmderstood that I do not limit my invention thereto since various modifications thereof will suggest themselves to thom skilled in the art without departing from the spirit of my invention. the scope of which=is set forth in the appended claims.

What I claim as new and desire to secure by Letters Patent oi the United States, is:

1. In a resetting device for a circuit controlling switch, the combination with a switch member movable between open and closed position, a pivot for said switch member, a device responsive to predetermined conditions for moving said switch member to closed position, an over-center spring connected to said device and switch member for obtaining a snap action of said switch member to closed position and (or maintaining said switch member biased to closed position when said switch member has been moved to the closed position, a tripping member mounted on w the pivot adjacent said switch member for moving said switch member to open position, said tripping member being provided with a beveled portion, a second spring biased to operate said tripping member to open said switch against the bias of said first spring, a bimetallic element for maintaining said tripping member in inoperative position against the bias of said second spring and responsive to overload conditions for releasing said switch moving member, of a reset member provided with a finger operable into engagement with said beveled portion to return said tripping member to initial position against the bias of said second spring, and resilient means on said switch member engaging said finger or maintaining said switch member in open position against the bias of said first spring as said finger is moved along said beveled portion to reset said tripping member.

2. In a reset mechanism for thermal switches, the combination with a switch member normally movable to open and closed circuit positions, a movable member provided'with an inclined portion, means pivotally mounting said movable member for movement into engagement with said member to open said switch, a bimetallic thermal element for normally retaining said movable member in a predetermined position against its bias to provide for independent operation oi said switch, a spring carried by said switch member in juxtaposition to said inclined portion. of a reset member provided with means movable in one direction to release said movable member and movable in another direction into engagement with saidinclined portion for operating said movable member to said predetermined posi-' tion and concurrently therewith for simultaneously engaging said. spring so as to maintain said switch member in its open circuit position.

3. In a reset mechanism for thermal control switches, the combination with a switch member normally movable to' open and closed circuit positions, circuit, opening means (or independently moving said switch member between said positions, a tripping member provided with an inclined portion arranged to be movable into engagement with said switch member to open said switch, means for biasing said tripping member in a direction to open said switch. a bimetallic thermal element for normally retaining said tripping member in a predetermined position against its bias, 01a reset member provided with means rotatable in one direction to release said tripping member for said bimetallic element and retatable in the oppositedirection into engagement with said inclined portion so that as said means is moved up, said inclined portion said tripping member is returned to said predetermined position, said means at the same time engaging said spring to bias said switch member to the open circuit position.

LEONARD P. HU'I'I. 

